USB Flash Drive Critical Problem...NEED HELP!!!!

Actually this problem occured once I installed the driver software for USB 2.0 card which was recently installed..during the installation process, I encountered a problem whereby the setup requires a file called "usbehci.sys" which was not detected in my PC..but that's not the problem, I found the file and completed the installation process. Now what happens after that is my Sony Flash Drive 2GB was detected as a removable disk with no storage size. But before the installation, the flash drive works just fine, i can still add any kinds of file, mp3's and other type of files, back then when I was still using USB 1.1 card in my PC. Now this problem really irritates me cause I got lots of personal files stored inside the flash drive, care to explain me how to fix this problem anyone. One more thing, before I installed the driver software for USB 2.0 card, I had to just pull out the flash drive without safely removing the hardware on the tray icon cause i was in a rush. Not so sure about the problem though. Need the ultimate solution for this problem PLEASEEE!!!!

usb flash drives are not robust devices and detaching one without going thru the correct process can damge the drive or corrupt the data. the easiest way to see if the drive is working is to try it on another machine.